As the title says, at some point, there were some LGA 2011-3 Motherboards for Haswell-E planned that had DDR3 Slots in them. Yet that news article is already 3 years and half old, and I think that I never hear about them again. Where the hell are those Motherboards? One has to guess that after 3 years, they should be already becoming available in the used market...
Considering the obscene prices of DDR4 Memory Modules and that DDR3 RDIMMs can usually be got for cheap, a Haswell-E/Broadwell-E platform using DDR3 would be an excellent alternative in the second hand market. I think that only a few specific Processor models had official DDR3 support, so Motherboard and Processor should be matched.
I also don't recall if Broadwell-E had a hybrid DDR3/DDR4 Memory Controller or not, nor Skylake-E status. Heck, Haswell-E was not supposed to support DDR3 on the first place...
Considering the obscene prices of DDR4 Memory Modules and that DDR3 RDIMMs can usually be got for cheap, a Haswell-E/Broadwell-E platform using DDR3 would be an excellent alternative in the second hand market. I think that only a few specific Processor models had official DDR3 support, so Motherboard and Processor should be matched.
I also don't recall if Broadwell-E had a hybrid DDR3/DDR4 Memory Controller or not, nor Skylake-E status. Heck, Haswell-E was not supposed to support DDR3 on the first place...